package com.example.directorydemo;

import android.annotation.SuppressLint;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    MyHelper myHelper;
    private EditText mEtName;
    private EditText mEtPhone;
    private Button mBtnAdd;
    private Button mBtnQuery;
    private Button mBtnUpdate;
    private Button mBtnDelete;
    private TextView mTvShow;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        myHelper =new MyHelper(this);
        init();
        initEvent();
    }

    private void initEvent() {
        mBtnAdd.setOnClickListener(this);
        mBtnQuery.setOnClickListener(this);
        mBtnUpdate.setOnClickListener(this);
        mBtnDelete.setOnClickListener(this);
    }

    @SuppressLint("WrongViewCast")
    private void init() {
        mEtName = findViewById(R.id.et_name);
        mEtPhone = findViewById(R.id.et_phone);
        mBtnAdd = findViewById(R.id.btn_add);
        mBtnDelete = findViewById(R.id.btn_delete);
        mBtnQuery = findViewById(R.id.btn_query);
        mBtnUpdate =findViewById(R.id.btn_update);
        mTvShow = findViewById(R.id.tv_show);

    }

    @Override
    public void onClick(View view) {
        String name, phone;
        SQLiteDatabase db;
        ContentValues values;
        switch (view.getId()){
            case R.id.btn_add:
                name=mEtName.getText().toString();
                phone=mEtPhone.getText().toString();
                db=myHelper.getWritableDatabase();
                values = new ContentValues();
                values.put("name",name);
                values.put("phone",phone);
                db.insert("information",null,values);
                Toast.makeText(this,"信息已添加",Toast.LENGTH_SHORT).show();
                db.close();
                break;
            case R.id.btn_query:
                db =myHelper.getReadableDatabase();
                Cursor cursor =db.query("information",null,null,null,null,null,null);
                if (cursor.getCount()==0){
                    mTvShow.setText("");
                    Toast.makeText(this,"没有数据",Toast.LENGTH_SHORT).show();
                }else {
                    cursor.moveToFirst();
                    mTvShow.setText("Name:"+cursor.getString(1)+" ; Tel : " + cursor.getString(2));
                }
                while (cursor.moveToNext()){
                    mTvShow.append("\n"+"Name :" + cursor.getString(1)+" ; Tel : "+ cursor.getString(2));
                }
                cursor.close();
                db.close();
                break;
            case R.id.btn_update:
                db=myHelper.getWritableDatabase();
                values =new ContentValues();
                values.put("phone",phone=mEtPhone.getText().toString());
                db.update("information",values,"name=?", new String[]{mEtName.getText().toString()});
                Toast.makeText(this,"信息已修改",Toast.LENGTH_SHORT).show();
                db.close();
                break;
            case R.id.btn_delete:
                db =myHelper.getWritableDatabase();
                db.delete("information",null,null);
                Toast.makeText(this,"信息已删除",Toast.LENGTH_SHORT).show();
                mTvShow.setText("");
                db.close();
                break;
        }
        }


    class MyHelper extends SQLiteOpenHelper{

        public MyHelper(@Nullable Context context, @Nullable String name, @Nullable SQLiteDatabase.CursorFactory factory, int version) {
            super(context, name, factory, version);
        }

        public MyHelper(Context context) {
            super(context,"itcast.db",null,1);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            db.execSQL("create table information("+
                    "_id INTEGER PRIMARY KEY AUTOINCREMENT,"+
                    "name VARCHAR(20),"+
                    "phone VARCHAR(11) ) ");
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

        }
    }
}